Hi Brett,
Indeed, there are a number of channels around, and I will try to clear the confusion:
This email group is for any kind of unstructured discussion. I also announce big features on this list.
The sub-reddit was created later and serves a similar purpose to this email group. I would prefer to use only reddit, because it has a few more features like polling and nested comments. But then, not everybody is on reddit, and it's a centralized service.
The uservoice site is great for collecting ideas from users in a structured way. Some of the suggestions there are from 2012, and I am still actively thinking or working on these, because I can query them all by number of votes, categories, etc.